OBJECTIVETo investigate the absorption characteristics and transportation mechanism Yangyin Tongnao granules in main effective fractions in Caco-2 cell model.

METHODThe safety concentrations of Yangyin Tongnao granules in main effective fractions in Caco-2 cells. A Caco-2 cell model was established to study the transport situations after the compatibility of Yangyin Tongnao granules in main effective fractions, and the content was determined by high performance liquid chromatography (HPLC).

RESULTP(app) of puerarin, ligustrazine and astragaloside were less than 1.0 x 10(-6) cm x s(-1), and their P(app) were hard to be close to atenolol. The oral absorption in descending order is shown as the following: puerarin, ligustrazine, astragaloside. After the compatibility between saponins and flavonoids, P(app) of astragaloside was improved obviously, which promoted the transport from apical (AP) to basolateral (BL); the compatibility of puerarin, ligustrazine and astragaloside showed a significant effect in the efflux of astragaloside and no change in the absorption transport of ligustrazine and puerarin at the same time. There is a great difference in bidirectional transport of representative component of each effective fraction, and P(app)(B --> A) was significantly greater than Papp(A --> B), which suggested that the efflux transport from BL side to AP side had an advantage in the three representative components of the three effective fractions in Caco-2 cell monolayer model.

CONCLUSIONAstragaloside, ligustrazine and puerarin may be malabsorptive compounds, and the three compounds may be discharged by the transport protein in small intestine membrane.